计及异频耦合谐波的模块化多电平矩阵变换器阻抗建模  

Impedance Modeling of Modular Multilevel Matrix Converter Considering the Differ-frequency Coupling Harmonics

作　　者：孙玉巍[1] 陶聪 付超[1] 常静恬 查夏新 李光辉 SUN Yuwei;TAO Cong;FU Chao;CHANG Jingtian;ZHA Xiaxin;LI Guanghui(Hebei Key Laboratory of Distributed Energy Storage and Microgrid(North China Electric Power University),Baoding 071003,Hebei Province,China;State Grid Shanxi Electric Power Co.,Ltd.Xixian New Area Power Supply Company,Xi’an 712000,Shaanxi Province,China;National Key Laboratory of Renewable Energy Grid-Integration(China Electric Power Research Institute),Haidian District,Beijing 100192,China)

机构地区：[1]河北省分布式储能与微网重点实验室(华北电力大学),河北省保定市071003 [2]国网陕西电力有限公司西咸新区供电公司,陕西省西安市712000 [3]可再生能源并网全国重点实验室(中国电力科学研究院有限公司),北京市海淀区100192

出　　处：《中国电机工程学报》2024年第S01期227-239,共13页PROCEEDINGS OF THE CHINESE SOCIETY FOR ELECTRICAL ENGINEERING

基　　金：河北省自然科学基金项目(E2019502172);中央高校基本科研业务费专项资金(2022MS072)。

摘　　要：模块化多电平矩阵变换器(modular multilevel matrix converter,M3C)是低频输电系统的核心装备,所连接异频交流系统电气量在变换器桥臂直接耦合,其桥臂电气量不仅含有两侧交流系统各自基频的整数次谐波,还含有二者交互耦合产生的非基频整数倍谐波分量(称为异频耦合谐波)。忽略子模块直流电压动态和异频耦合谐波、以基频为频率间隔的多谐波线性化建模方法,难以准确刻画M3C的谐波特性,影响阻抗模型的精度,无法揭示子模块直流电压动态及谐波对阻抗特性的影响机理。论文首先基于M3C谐波特性分析,建立考虑两侧交流系统异频耦合谐波的多谐波向量频域模型,并通过M3C 9个桥臂多谐波小信号的相序关系和传递关系分析得到M3C单桥臂主电路小信号模型,降低阻抗建模复杂度;在此基础上,进一步考虑控制环路频率耦合效应的影响,建立能够准确反映直流电压动态和谐波特性影响的M3C序阻抗模型。最后,在RT-Lab实时仿真平台上通过时域仿真和扫频实验,验证M3C阻抗模型的准确性,并对影响阻抗特性的关键因素进行分析。The modular multilevel matrix converter(M3C)is the core equipment of the low frequency transmission system(LFTS).The two AC systems with different frequency that M3C is connected to are directly coupled in the converter arms.And the arm electrical quantities contain not only the integer harmonics of the fundamental frequencies of both AC sides,but also the non-integer order harmonics generated by their interactive coupling(called differ-frequency coupling harmonics).Ignoring the dynamic DC voltage of the submodule and the differ-frequency coupling harmonics and taking the fundamental frequency as the frequency interval,the multi-harmonic linearization modeling method is difficult to accurately describe the harmonic characteristics of M3C,thus reduces the accuracy of the impedance model.Moreover,it cannot reveal the mechanism how the DC voltage dynamic of the submodule and the harmonics affect the impedance characteristics.In this paper,based on the harmonic analysis of M3C and considering the differ-frequency coupling harmonics,a multi-harmonic vector model in frequency domain is established firstly.Through analyzing the phase sequence and transfer relations of the multi-harmonic small signals of the M3C 9 arms,the M3C power stage model can be reduced to that of one arm,so the impedance modeling complexity is reduced.On this basis,the impedance model of M3C is developed including the effects of control loops coupling that can accurately reflect the impact of DC voltage dynamic and harmonic characteristics.Finally,the accuracy of the M3C impedance model is verified through RT-Lab real-time simulations and sweeping experiments,and the key factors affecting the impedance characteristics are analyzed.

关 键 词：低频输电系统 模块化多电平矩阵变换器 阻抗建模 多谐波线性化 异频耦合 

分 类 号：TM712[电气工程—电力系统及自动化]